Door check mechanism



July 22, 1952 M. CARLSON DOOR CHECK MECHANISM 6 Sheets-Sheet 1 Filed April 12, 1948 IN V EN TOR. ML in Carlson W I i A I y 1952 M. CARLSON 2,603,818

DOOR CHECK MECHANISM Filed April 12. 1948 6 Sheets-Sheet 2 IN V EN TOR. 2mm tin (brlson July 22, 1952 M. CARLSON DOOR CHECK MECHANISM 6 Sheets-Sheet 3 Filed April 12, 1948 INVENTOR. marlin Carlson July 22, 1952 M. CARLSON ,603,

' DOOR CHECK MECHANISM Filed April 12, 1948 I e Sheets-Sheet 4 9 INVENTOR.

B '77Zartin Carlson July 22, 1952 M. CARLSON 2,603,818

DOOR CHECK MECHANISM Filed April 12, 1948 e Sheets-Sheet 5 IN V EN TOR. martin Carlson July 22, 1952 M. CARLSON DOOR cmzcx MECHANISM 6 Sheets-Shet 6 Filed April 12, 1948 w H m a m C .n m

'as'tationa'r'y or'in a checking position.

Patented July 22, 1952 UNITED STATES PATENTV'IOFFICE -Martin Carlson, Brookfield, lll gassignor hyzmesne assignments, to George W. fiHoulsby, .513, 011i- .18 Claims.

.1, My invention relates I a door check particu larly adapted for controlling the movement of swinging doors which move on both sides of the center or closed position. Some of the features of the'inv'ention, however, areadapted to be employed with "doors which swing to onlyone side of the center or closed position.

"The principal object of the inventionis the provision of a simple door check mechanism which is more positive in its operation and longer lasting under' ordina ry conditionsof use.

'Another object is the'provisio'n of an improved simple door check mechanism in which. wear is positively compensated for andwherein'such wear as does occur will not 'impair the functioning.

. izstill another object of the invention is the provision of a door check mechanism so :con-

structed and arranged "that the door will "come back "to a center or closed position and will be retained at the center or closed position even thoii'gh forces, as of the-wind blowing against it, are present which would normally tend to move the door back "awayirom center.

Still another object is "the provision "of an fitnp'r'ove'd siinpl'e door check mechanism which the heokingactibn is effective "u 'to and beyond the center or' full' closed position.

'A iu'i ther object is the provision of a 'simple doo'r 'check mechanism which will not swin 'past eenter as itiscldsing.

A-"still further object o'f the inventioniis' the provision of an improved simple door ch'e'ck mechanism "in' which the initial checking iaction permits relatively rapid nio'veme'nt of the .door

and' the fi-nal "checking i action before fully closed permit the door to be -piished rapidly either direction" regardless of whether -o'r not itis at 'Other-specifi'c objects and featiire's-o f the invefitic'n will ts ortnight but in connection with the followin'g ='de'tailed description "taken With the accompanying urawmgs wherein:

F'ig; is a nagm'entar y partiany schematic perspective "View showing the door c'hekmehanism of my ihvehtion in conventional position with respect to a swingingdoor;

Fig. 2'is a'-plah"-view df the door' ch'eck showing severalpositions of the door; I

Fig- 3 ts a ir aginentarysection-a1 view "taken on the line of Fig. 1',:-tl'1e view oing em 2 larged with respect to Fig. 1, but the parts he! ingapproximatelyin'full scale;

Figu iis a perspective view of a sealing g'asket used-to=preventoil:leakage; P

Fig. 5 is a fragmentary exploded perspective View showing the manner in which the doo'r is hung; l

Fig. 6 is a longitudinal sectional view taken on the line 6-6 of Fig. 1, "the view also being enlarged :with respect to .Fig. 3, and parts of {the door being broken away :for purposes of tillllS- tration; I V V Fig. 7 is :a bottom plan Section taken .-on' .the line 'l"l of Fig. 6, looking in the direction- '0! the arrows;

'Fig. 8 is :an irregular 'bottom plan section taken on the line =8-'8 of Fig. '6 looking *in'zthe direction of'th'e arrows;

Fig. 9 is 'aview 'similarto Fig.8 "butillustrating %-the movement of some of the parts when the door swings fully but just short of theihold open position;

. Fig. .10 is ,:a view similar to Figs.:8 and 29, but

showing the-position of the parts when :thedoor is inrh'oldwpen position; "Figs 11 is an irregular transverse sectional View taken'on :the line I l.'-| l "of Fig. '7, looking in the directionofthe-arrows;

Fig. 1-2 is a fragmentary vertical sectional view taken on the line [2-12 of *Fig. 7.; :Fig. 13 :is ta fragmentary I sectional view taken on theline 'l'-3l3 of 'Fig. 12, looking inythewdi' rection of the arrows, the section showing the high speed hydraulic exhaust .port and indicating the passagewaythrough whichzoilrflowsirom the 'slowspeedexhaust p ort 14 :is a fragmentary transverse sectional view taken on :the .lline :1'4-454 .of Fig. .13;

Fig. 15 isa sectional "view ta-ken-aon :the line ii-l5 of :Fig. :12 showing the :slowspeed Phydraulicrport; -Fig. 1'6 is a transverse sectional view takenon the li'ne I'fi'-+-I 6 :of Fig. :11,.looking inthedirection of-theiarrowsra; portion :of .thE'SBCtiOIlFbiI'l-fi slightly irregular in order --that. the.;hydrau1ic piston i might be shown s'substantially in zcenltral 'sectionforrclearness;:and I Fig. :17 :is 'a sectional view similar :to 6, but showing a structural. modification.

The doorch'eck mechanism shown in. them-am embodiment of the invention-comprises anassem lily-20 (Fig.1) adapted toset in the floor 2| and, ma -manner to bedescribed, toa'ctzas a lower hinge orfpivot or a swingingdo'or' 22. The 'manner of attachment-between the door a-ndspindle center race of the radial bearing to form the pivot. The bracket 25 is recessed and lies flush with a lintel or upper frame cross piece of a doorway and includes a plate 27 which closes the j recess in which the bracket is mounted. A pair of gears carry a pin 28 onwhich a lever 29 is' pivoted. The forward end of the lever projects into a side recess of the pivot pin 24 and the opposite end is bifurcated to engage around a narrowed portion of an adjusting screw3l. ,By means of this construction, the adjusting screw may be retracted to actuate the lever 29 and raise the pivot pin 24 to release the door. Contrariwise, when the screw 3| is turned into the bracket 26, the pivot pin 24 is lowered into engagement with the radial bearing 23 to retain the'door in swinging position. i I

As already'noted'themounting of the door on the door check spindle will be describedlater. All of the parts of the door check mechanism are supported on a mounting plate 32, the four corners of which are fastened to inwardly extending'e ars' 35 at the corners of a metal case 33 by screws 34 which extend through openings 36 in corners of the mounting plate; The case 33 is preferably set into' cement 31 or other material forming the floor, but, in any case, the case 33 should be firmly secured in position. A housing 38 secured to the bottom of the mounting plate by screws 39 and a gasket 4| is placed between the'bottom of the mounting plate and the flange ofthe housing to make an oil tight connection. A cylinder block casting '42 is also secured to the bottom of the mounting plate by screws 43. This casting carries the door check mechanism includ- 'inga hydraulic door check piston, and such casting also extends down into a deeper portion'of the housing 38 which thereby acts as an oil sump. When the mechanism is installedythe housing 38 is filled with suitable oil or other hydraulic fluid to a point extending somewhat above the sump portion of the housing, but the arrangement employed is such that even after long periods of use and even if there should be some slight loss of fluid, there will always be enough hydraulic fluid in the sump to assure proper operation of the'check mechanism..

A spindle 44 projects vertically from the door check mechanism, being supported at the bottom by a bottom bearing plate '46 and at the top by an upper bearing member 41, each so constructed and arranged as'to retain bearingballs 48, the bearing balls also being supported by shouldered and-rounded portions of the spindle. The bottom bearing plate 46 is secured to the cylinder block casting'42 by screws 49. The bottom bearing plate 46 is made strong and relatively heavy and is firmly anchored to the cylinder block casting 42, which, in turn, is secured to the mountin pl'ate'by screws 43. This plate is, therefore, able to take the'full load of the door and the parts 4 tion radial and thrust bearing. By this means a very firm but very free moving support is formed for the spindle 44. A specially formed synthetic rubber packing ring 5| is interposed between the spindle 44 and the inside wall of the bearing member 41. The bearing is thereby sealed against entrance of dirt and loss of oil along the spindle. The door checkmechanism is so constructed and arranged that when the door is opened energy is stored into a spring structure to provide means for automatically "returning the door to closed position and at the same time hydraulic fluid is drawn into a cylinder, said cylinder having a piston which returns to normal position against a hydraulic head at a controlled rate as the door is returned to closed position by the spring structure. To bring about these operations, I provide an actuating cam 52 which is integral with the spindle 44 and immediately below it a check cam 53 which is supported on the spindle and secured'thereto by a key '54 (note Fig. 16) arranged to provide a slight amount of motion (on the order of 10 degrees) between the spindle and said check cam. The end of the cylinder block casting is centrally recessed. to provide space for these cams so that they can rotate freely. r Looking first to the spring structure and its relation to the actuating cam '52, I provide a pair of rods 56 which are reciprocable in aguide block 51 mounted to the underside of the mounting plate 32 and have narrowed portions extending into a slide bearing 58 at the ends adjacent the actuating cam 52. The rods 56 are threaded at 59 to receive adjusting nuts 61 and actuating springs 62 are mounted on the rods and com: pressed between the guide block 57 and the adjusting nuts 6|. By turning the adjusting nuts on the screws '59, the initial compression of the springs 62 can be controlled. While the means for turning the adjusting nuts may vary, I have found it suitable to provide peripheral openings 63 whichcan be reached with a tool by removing a circular closure 64 in the plate 32.

The relation of the guide rods 56 to the slide bearing 58 is such that they move together, and this is preferably accomplished by providing a press fit between the narrowed ends of the guide rods and the holes in the slide bearing, pins 68 being utilized also to assure holding the rods in place. The slide bearing 58 engages below the mounting plate 32 and against the sides and top portion of the cylinder block 42 within the upright portion thereof as shown in Figs. 8 and 9. As a result, the slide bearing 58 and guide rods may be moved as a unit against the compression of the actuating springs 62, even though pressure may be applied a one side or the other of center. The slide'bearing carries two rollers 61 on pins 68 at opposite sides of center, such rollers adapt ed to engage the actuating cam 52 to perform several functions which will be pointed out. A roller is shown (in section in Fig. '12) ascomprising a plural part structure to facilitate fabrication and provide for wear resistance at critical areas. Suitably, the pin 68 is relatively soft and carries a tight hardened bushing against which the hardened exterior bushing comprising the roller rotates. At least one of the rollers 61 engages an actuating cam 52 at all times and when the door is at the center or closed position, both of the rollers engage the shoulders 52-a (note particularly Fig. 8) which are contiguous to cam portions 52-22. The cam portions terminate in points-52-c with hold-open recesses 52-d .con-

aeoaars :5 atiguous i-thereto and an .-arcuate iportionwfleiin- --terconnecting lthe-twohold-open recesses. Keep- =ing inv mind. that the spindle and-factuating cam rotate about' the center of the' spindle -as\the-dor ris .opened, it "will be noted that movement in eithendirection (see Fig. :9) "moves theqguide :bar assembly-in 1 such a position as-to ifurther eom- .pressithe actuating springs, and that thee-am rportionse52 iareso shaped thatithere :i az continu- 'ouslygreater movement as the door is opened wider. There are :some 1 additional-features with respect to the shape of the'cam,;particularly as 110 the hol,d openfiunction, but such :ieatures will aha-explained :further in .connection with -.the-1opstation. .It is sufficiente-to :note :here tha-t since .the :compression springs :are increasingly com- ;pressed :iniresponse to "opening;movement i of "the door, ;;release :of the door permits the-springs to continuously urge-the door :t'o .closedipo'sition until ea; point is :reach'edat i which the two :sliding :rollers .rest :against .the shoulders :52-a; During the ireturn rmovement of the 'd0or,=the-.1Spring ac- 'tion is damped :by the hydraulic -c'heck mecha- 'nism'which will 'nowtbe described The cylinder block is provided'with acylin- -drical; portion in which a hydraulic piston or ram -69 risrreciprocable. The exterior end of .the "hy- =-draulic'piston-isshapedzto receive aip'inil carrying-a roller 12 which is adapted to-engagewthe .checlccam 53. As'may -be seen most clearly by reference to Figs. "6, l and -r16, thewcheck' cam is symmetrical" as to fits two sides and generally comprises ='an .eccen tri'cally imounted :oval :with "a anoint; at:the"end'facingzthe check roller 'l2 so that .as the door is returned xto :closed YpOSitiOn, from either side; the hydraulic: piston'zfi'l will be forced 'intofthe cylinder. A piston texpanding :spring 1'13 =isidisposedin a hollow :portion'of ithezpiston and engages :against the "cylinderfhead 'to'zretra'ctlthe piston :as the "check cam .moves away ifrom fthe "checkmoller l2. A'stud M "(Fig 16) has a narrowed tend-portion projecting into a side slot of .the :pis'tonto :prevent complete withdrawal of theipiston and also to"prevent rotatoryimovement thereof.

As the piston is withdrawnbyth'e actionof'the spring :13, hydraulic'fluidiis-drawniiiito the cylinder, and as the piston is-forced back into "the :cylinder, the hydraulic fluid is forced 'irom' the :piston through "control orifices to perform a checking or dampingfunotion. The "oil is "drawn through an intakepassageway 16 in which a "check valve ill, inthe form of a ballkengag'in'g against :a seat, is provided. A- ball retainer =18,

in the formaofanarrowmod,:havingra threaded vide a low speedpassageway 1-9 and'a "high speed passageway =81, both communicating with the 'inside-ofthe cylinder sothat hydraulic fluid may be foreed "thereinto. A tapered valve 'stem =82 is secured within *the side wall of the f-piston'by a -pin" 83, the parts being relatively loose so that :som'ef wobblingsotthe valve stem -ls perm-ittedefor alignment in ther'high speedspassageway. The high speed ,Ipassageway '1 communicates with sanlother passageway 84 Jrunning :at aright angles thereto, 'andfjust befow the 'highspeedipassageavay meets; the ;;passageway 84, the high :speed passageway-is restricted towengage theilargest :portionof the valve stem 82 somewhat-snugly. The apassageway 84 "formsv a v part of the high -speedipassageway and therresult of'lthis. arrangement 1' is 1 such that when the ;piston is :substantial'ly fully .rretracted theztapered portion ot the valve stem 282 permits'ifree flow ofnoil aroun'diit lito the passageway :"84; but when the-return movement oflthea pistonrha .beenzpartially completed the largest portion .of athe "valve ristem 582 ?iunctionsmwith the wall ::of :the passageway Pas-1a valve .to: substantially: shut: ofi 'iurthe1* ?fiow of hy'- drauliofiuidtthroughftherhighzspeed passageway. LoOkingzatEFig. .16,; it will beinotedthat the 1pas- --sageway :84 :has an :extension iindi'cated by th'e .rreferenc'e .charact'eria l'. Those skilled in theart williunderstand that this is merelyi'a device for :drilling .the passageway 84. "Closure of the -pas- :sa'geway extension 84' by a plug 86 prevents dis- Toharge 0f hydrauliefiuidiinfany dir ection except through the control valve which *will now :be described.

Running-at rig-h tangles' to each 'of the'passa'geways heretofore-referred to is passa'ge'Way Bl ter-v minating at '88 in an outlet or exhaust through whi'ehithe hydraulic 'fluidis -returned to -thesump. Within acontinuation df the peassageWay B l, is disposed a valve m'ember 89 wh'ich p'er form's -the function of controlling release 'of hydraulic 'fluid'through both the high speed-and low speed passageways. The valve member '89 is iadj ust'ably threaded in the cylinderblo'ck at -9:I and it has an upper extending portion-'92 conven-iently positioned below the circular-closure '68 soias tobeadjustable upon removal-of said closure; Aspring '93 is placed-in the passage way 28'! and compressed against the end of the valve member ES to supply enough 'resistaneeso that the valvemember afi will beheld in any position' to which it is adjusted. As will benote'd particularly by reference to Figs. I2, -13 and 16, J'the-pas'sageway 84 discharges into an enlarged portion-of the passageway 81 and-"exterior of the valve member 89. 'Thevalve-m'eniber 89;however, :has a tapered edge recess "9'4 '(note particue 'Iarly Figs. :13 and 14) at its loweren'd 'just at' the point where the enlarged portion of'the passage- :way i8lils narrowed down to" fit snugly against the 'iex-terior of the valve member 89. The edge tr'ecessififl, therefore, forms the only outlet for hy-' dr'aulic "fluid irom the passageway 84 -to"-the"ex- :hau'st port 88. This passageway is largeror smaller'fldependi'ng upon how .m the-valve mom ber 789 *extends into the: narrowed portion o'f 'the ;pas'sageway 81,* immediately adjac'ent' ito thefexhaust port 88. Sin'ceth-isposition is readilycon trolled byturning'the valve member on its threads 9 I adjustment offr'ate o'f flow through the "high :speed passageway and high speed port 'isreadily adjusted. It is not necessary for "the service attendant to be "able to see the exact 'aclj ustment of" the :port because the adjustment is "on a ifun'c tional basis. .If "the ifiISt movement of the door is too srap'id, he merely tightens the valvememheruntiltheiproper rate of flow is obtained. If therexshould :be wear a'tthehigh speed port-this is:automaticallyztcompensated for when ithe device iswadiusted*during routine servicing;

:F EITh'e 510W tsp'eed passageway 19 mommuriieate's '7 with the'passageway 81 (note Figs-12 and 15) at a point where the valve member 89 is enlarged immediately adjacent the threaded portion 9l so that the only escape for hydraulic fluid from the passageway 19 is through a radial port '96 in the valve member and an axial bore 91. The radial bore 96 extends entirely through the valve member and the exterior surface of the valve member'is preferably slightly notched at the outer ends of the port, as shown in the drawings, to increase the number of positions of the valve member at which communication can be established between the passageway 19 and the interior bore of the valve member. It will be noted that there are two positions/in the rotation of the. valve member at which maximum flow is permitted through the'low speed passageway and four positions at which more restricted but identical rate of flow is permitted through such passageway. By placing thescrew driver slot or other tool engaging formation or separate identifying point on the upwardly projecting portion 92, the position of the radial port 96 can be established and only slight manipulation by the service attendant is necessary to control the movement through the axial port which, of course, comprises the controllable orifice for the low speed passageway. Slight rotation of the valve member for adjusting the low speed port is without substantial effect on the adjustment made with res ectto the area of the high speed port.

I provide means for by-passing both the high and low speed passageways so that there may be a more rapiddischarge of hydraulic fluid, if a person going through a door should force it in a-closing direction at a more rapid speed than would be normal to ordinary automatic closing movement. To this end, I provide a passageway 98 normally closed by a valve 99 which is forced against its seat by a spring lfll, in an enlarged portion of the passageway 98 by a plug I02. Passageway 98, at its enlarged portion communicates with side passageway I03 to which tubing I 04 is connected, the tubing I04 extending around and discharging at the point I06 against the spindle 44, immediately adjacent the upper ball bearing. Spring IOI is made strong enough so that in ordinary operation, the ball 99 will be retained against its seat, but when more than usual pressure is applied against a door to force the piston 69 into the cylinder, pressure of hydraulic fluid within the cylinder will force the ball 99 away from its seat and discharge hydraulic fluid through the tubing I04. I project the hydraulic fluid so discharged against the upper part of the mechanism to assure continued oiling thereof. It is, of course, obvious that when pressure is released there will be no further discharge through the passageway 98, and the rate of discharge is moreor less directly proportional to the pressure applied against the door and-the extent to which the ball is forced away from its seat.

In employing theterms high speed passageway and high speed port as contrasted with low speed passageway and low speed port it should be borne in mind that these terms are employed to explain a function and not necessarily the relativesize of the passageways and ports involved. What I have called a high speed passageway is the one which is open only during the relatively rapid return movement of the door, it being understood that the low speed passageway and low speed port are open during the entire door movement. In other words, the construction is such that both ports are functionally 'openduring the first part of the door movement to permit rapid closure, but one of the ports 'is closed before the other so that the rate of flow from the cylinder is decreased and'the final door movement is reduced in speed. I wish to note that while I have referred to by-passing the high and low speed ports to permit oil to flow through the tube I04, only a portion of the hydraulic fluid takes this route since one or both of the ports will continue to pass hydraulic fluid even at the time hydraulic fluid is being delivered through the tube I04. I v

In anearly part of the'specification, I referred to the provision of a slight amount of movement between the check cam 53 and the spindle 54. This is brought about suitably by providing a rel- 'atively wide keyway ill! forthe key 54, as shown spindle. The result is that when the door, spindle and actuating cam have returned to center or closed position, the check cam is still slightly short of dead center. The spring 13 which, of course, is

much Weaker than the two actuating springs is now compressed substantially its maximum amount but, as will be noted in Fig. 16, there is still room for continued slight movement of the piston. To move the piston forward, however. the spring 13 would have to be compressed and it cannot be compressed by the further "action of the actuating springs 62 because at this time the actuating springs and actuating cam are in the position shown in Fig. '8. It would, therefore, be necessary to apply some force to the door to move it past dead center and compress the spring 13. When the door has been opened in one direction, it is prevented from swinging past dead center by this construction, and the construction also prevents the door being moved by the action of wind or the like. When a swinging door is caused to move by the action of the wind, a rhythm is set up so that the door frequently oscillates on both sides of dead center. If, by any chance, a strong wind should blow the door in a direction such that the spring 13 would not be compressed by it, the action is such that the door would swing back and establish such a relationship of parts that further swinging movement would be prevented.

I referred in an earlier part of the specification to the use of the spindle 44 as the lower hinge or pivot upon which the door pivoted. While various constructions may be employed to mount the door on the 'spindle (separate mounting means may, of course, be employed and the spindle merely actuated by door movement), I indicate in Figs. 1, 3, 5 and 6 one suitable arrangement. Here the spindle is flattened to project'into a slot I08 on a hinge member I09 which engages in a recess at the bottom of the door. The door has a steel plate I I l with a downwardly extending pin I I2 which engages in a slot H3. A set screw H4, which is threaded in the end of the hinge member, positions the hinge member and pin H2 with respect to each other. The weight of the door is such that the pin H2 tends to bear against the end of the set screw H4. Thus, the hinge member H19 is fixed with respect 11* still adequate to prevent introduction of appreciable quantities of dust and dirt and loss of hydraulic fluid.

The door return springs preferably operate in compression and, in a sense, are opposed by spring 13 which is also in compression. The principal function of spring 13 or other means employed to retract the piston 69 is to maintain contact with the check cam 53. This is part of the construction which secures the objects of the invention having to do with wear of the parts, it being obvious that even aftercontinued use the door will never have a point at which there is lost motion'between the spring action and checking action. The hydraulic checking action, in other words, always opposes the return spring action gaging the actuating cam for return the same to normal position, a hydraulic cylinder, a piston reciprocable therein, a check cam carried by the spindle, spring means urging said piston against the check cam, the parts being so constructed and arranged that the piston is retracted as the door is opened, means to draw hydraulic fluid into the cylinder as the piston is retracted, ad-

justable port means for restricting expulsion of said hydraulic fluid, said door returning spring means being checked by restriction of said hydra'ulic flow, and a lost motion connection between the spindle and check cam.

2. In a door check of the character described, a spindle rotated by door movement, an actuating cam carried by the spindle, spring means engaging the actuating cam for returning the same to normal position, a hydraulic cylinder, 1.

a piston reciprocable therein, spring means urging said piston out of the cylinder, 'lost motion means associated with the spindle for returning the piston into the cylinder, the parts beingso constructed and arranged that the piston is retracted as the door is opened, means to draw hydraulic fluid into the cylinder as the piston is retracted, and adjustable port means for restricting expulsion of said hydraulic fluid, said door returning spring means being checked by restric: tion of said hydraulic flow. I f a 3. In a door check of the character, described, a spindle on which the door is adapted to'be mounted for swinging in either direction, an actuating cam integral with the spindle, a spring assemblyincluding'at least one spring under compression and a roller ngaginga'gainst the said actuating cam, a cylinder body mounted below the said spring assembly, a piston within the cylinder, a spring within the cylinder urging the piston out of the cylinder. a check cam on the spindle, means providing a lostmotion connection between the checkcam and "spindle, a roller carried by the piston riding on the check cm. a casing forming a hydraulic fluid'sump aroundthe cylinder, an inlet port and outlet port between the said sump and cylinder, and-means to, control discharge of fluid-through the 'said outletport. 11., V

; 11. ,In a door checkof the character described;

12 a spindle on which the door'is adapted to be mounted for swinging in either direction, an actuating cam integral with the spindle, a spring assembly including at least one spring under compression and a roller engaging against the said actuating cam, a cylinder body mounted below the said spring assembly, a piston within the cylinder, a spring within the cylinder urging the piston out of the cylinder, lost motion means associated with the spindle for returning the piston into the cylinder, a casing forming a hydraulic fluid sump around the cylinder, an inlet port and outlet port between the said sump and cylinder, and means to controldischarge of fluid through the said outlet port.

5. In a door check of the character described, a mounting plate adapted to be set flush with the floor near a door opening, a cylinder block secured to the bottom of the mounting plate, a spindle projecting upwardly through the mounting plate and having upper and lower bearings carried by the mounting plate and cylinder block, respectively, an actuating cam on the spindle below the mounting plate and above the cylinder block in a centrally recessed portion thereof, a slide bearing below the mounting plate and between upright portions of the cylinder block, a pair of guide rods having their ends secured in the slide bearing and reciprocably supported in a guide block carried by the mounting plate, springs surrounding the guide rods and adjust ably compressed against the guide block to force theslide bearing toward the actuating cam, roller means on the slide bearing engaging against the actuating cam, a piston disposed in a cylinder portion of the cylinder block, a spring forcing said piston outwardly, a connection between the spindle and piston for returning the latter into the cylinder including a crank having a lost motion connected to said spindle and pitman means connecting said crank to said piston, a casing for hydraulic fluid secured to the mounting plate and entirely enclosing the structure mounted below the mounting plate, means for drawing hydraulic fluid into the cylinder when the piston is withdrawn, and controllable means for limiting flow of hydraulic fluid from the cylinder.

6. In a door check of the character described, a mounting plate adapted to be set flush with the floor near a door opening, a cylinder block secured to the bottom of the mounting plate, a spindle projecting upwardly through the mounting plate and having upper-and lower-bearings carried by the mounting plate and cylinder'block,

respectively, an actuating cam on the spindle below the mounting plate and above the cylinder block in a centrally recessed portion thereof, a slidebearingbelow the mounting plate and be} tween upright portions of the cylinder block, a pair of guide rods'having their'ends secured-in the slide :bearing and reciprocably supported in a guide block carried by the mounting plate,'springs surrounding the guide rods and adjustably conipressed-against the guide block to force the slide bearing toward the actuating cam, roller 'means on the slide bearing engaging against the actuat ing cam, a check cam-carried by the spindle be low the actuatingcam', a lost motion connection between the check cam andspindla'a piston disposed in a cylinder portion of the cylinder block, a roller on an exterior portion of the piston,"a spring forcing said'piston roller into contact. with the check cam, a casing' for hydraulic fluid secured to the mountingplateand entirelyenclos ing the said apparatus mounted below the mount ace-agate ing"platc,;means' for drawing "hydraulic "nine intot-he cylinderwhen the piston is withdrawn; and controllable means for limiting-flow 'of hydraulic fiuid'fromthe cylinderm- 7. In *a door check of r the character described, a mountingplate adapted-to be set flush-with the floor near a door opening, a cylinder block secured to the bottomof the-mounting plate, a spindle projecting upwardly through the mounting'plate and having upper and lower bearings carried by the mounting plate and cylinder block; respectively, an-actuatingcam on the spindle below' -themounting plate and above the cylinder blockin a centrally recessed portion thereof,- a slide bearing below the mounting plate and between-upright portions of the cylinder block, a pair'of-guide rods having-their ends secured in the-slide bearing and reciprocably supported in a guide block carried bythe-mounting p1ate,:springs surrounding the guide rods and adjustably "compressed against'the guidebloek to force the slide bearing toward the actuating-cam, rollermeans on the slide-bearing engaging against the actuating'cam, a checkcam carried by the spindle below the actuating cam; a-key carried by the spindle in an 'enlarged-keyway on the cam whereby to form a lost motion connection, a piston disposed in a-cy1inder portion of the cylinder lblOCk, a roller on an exterior portionof thepiston, a spring forcing said piston roller into contact with the check cam, aliasing for hydraulic-fluid secured to the mounting plateand entirely enclosing-the saidapparatus mountedbelow-the mounting apla'te. means for drawing hydraulic fluidin'to thecylinder when the-piston is-withd'rawm-and controllable means for limiting low of-hydrau1ic fluid from the cylinder.

'8, in ado'or check of the characterdescribed, amounting plate adapted to be set flush with the floor near a door opening, 'a' cylinder'block secured to the bottom of themountin plate, a spindle projectingupwardly through the mounting plate and having upper and lower bearings carried by the mounting plate and cylinder block, respectively, an actuating cam on the spindlebelow the mounting plate and above the cylinder block in a centrally recessed portion thereof, a slide bearing below the mounting plate and between ;upright portions of the cylinder block, a

pair of; guid ods. ha ng t icirlends secured in athe l de bea ing and reci rccably supported in a ui e ck. car ie y the-m plate, springs surrounding theguide rods and adjust ably compressed against the guide block to force the slide bearing toward the actuating cam, roller means on. the slide bearing engaging against the actuating cam, a check cam carried by the spindle below the actuating cam, a piston disposed in a cylinder portion of the cylinder block, a roller on an exterior portion of the piston, a spring forcing said piston roller into contact with the check earn, a casing for hydraulic fluid secured to the mounting plate and entirely enclosing the said apparatus mounted [below the mounting plate, means for drawing hydraulic fluid into the cylinder when the piston is withdrawn, controllable means for limiting flow of hydraulic fluid from the cylinder, and means for delivering hydraulic fluid directly from the cylinder against said upper hearing when closing force is applied against the door substantially above that exerted by said actuating springs.

9. In a door check of the character described, a spindle rotated by door movement, an actuating cam carried by the spindle, spring means en- 'ga'gingthe actuating cam returnin the -sam e -to normal position, a hydraulic cylinder,-a piston reciprocably therein; a check .ca-m carrie'd bythe spindle, spring means urgingsaid pistonagainst the check cam, the parts 1 tan so constructed and arrangedthat the piston is retracted as the door is opened, means" to draw hydraulic fluid into the cylinder as z-the piston is retracted, and adjustable port means for restricting expulsion of said hydraulic fiuidgsaid doorLreturning spring means being checked by restriction of Asaid- =hy-' draulic flow, saidactuatingcam having a sharply recessed portion at the door at. rest position, :a camportion of gradually increasing radius, arecessed door hold-openposition, anda sharp rise in the said-cam-portion immediately before the hold-open position.- I w 10. Ina door check ofthe-character described; a spindle rotated by doormovement,- an actuating camcarried by the spindle, spring means engaging the actuatingcam returning the same to normal -position,fla hydraulic cylinderya pistton reciprocable therein, acheck cam-.carried-by the spindlaspring means urging said piston against the check cam, the parts beingiso constructed and arranged that the piston -isretracted as the door is opened, means to draw hydraulic 'fluid into the cylinder as the piston .is retracted,and adjustable port means for-restricting expulsion of said hydraulic fiuid,-:said -door returning spring means being Jchecked' by arestriction of said hydraulic flow, said actuating cam having a sharply recessed portionatithe door at rest position, a cam portion .oflgradua'lly increasingradius, a recessed doorhold-open position, and a sharp rise in the said campor-tion immediately before the hold-open position, and a sharp rise past the hold-open position, so that increased pressure is required :to. movevthedoor immediately into and past the holds-open :DOSie tion.

ll. In a door'checlsof the character described;

a spindleon which the door is adapted ,to be mountedfor swinging in either direction,i an ac.-

tuating cam integral with the spindle, a spring assembly including at least one spring under compression and a roller engaging against :the said actuatingcam, a cylinder bodymount'ed'below-the said spring-assembly, a piston within the cylinder,a spring within the cylinderurging the piston out of the'cylinder, a check. camgort the spindle,'a rollercarried by the piston ridinglon the check cam, a casing'forming ahydraulic fluid sump around thecylinder, anlinletiportsand outlet-port between thesaid sumpand-cylinder,

and means to control discharge of; fluid through the said outlet port, said actuating cam having a sharply recessed portion at the door at rest position, a cam portion of gradually increasing radius, a recessed door hold-open position, and a sharp rise in the said cam portion immediately before the hold-open position.

12. In a door check of the character described, a mounting plate adapted to be set flush with the floor near a door opening, a cylinder block secured to the bottom of the mounting plate, a spindle projecting upwardly through the mounting plate and having upper and lower bearings carried by the mounting plate and cylinder block respectively, and actuating cam on the spindle below the mounting plate and above the cylinder block in a centrally recessed portion thereof, a slide bearing below the mounting plate and .between upright portions of the cylinder block,

the slide bearing and reciprocably supported in a guide block carried by the mounting plate, springs surrounding the guide rods and adjustably compressed against the guide block to force the slide bearing toward the actuating cam, roller means on the slide bearing engagingagainst the actuating cam, a check cam carriedby the spindle below the actuating cam, a piston disposed in a cylinder portion of the cylinder block, a roller on an exterior portion of the piston, a spring forcing said piston roller into contact with the check cam, said actuating cam having a recess into which said piston roller may drop to provide a hold-open position, said cam being characterized by a sharp rise before and a sharp rise past the said hold-openposition, so that increased pressure is required to move the door immediately into and past the hold-open position;

13. In a door check of the characterdescribed, a spindle on which a door is adapted to be mounted, spring means tensioned when the spine dle is rotated and functioning to return the spin dleand door toeclosedposition, a hydraulic piston retracted when the door is opened to withdraw hydraulic fluid from a source of supply when the door .is opened and adapted to be returned with a hydraulic check action when the door is closed by the springs, anda lost motion driving connection between the spindle and piston, so that the said checking action extendsup to and beyond fully'closed position.

14. In a door check of the character described wherein a rotatable ,camv responsive to' door movement energizes a spring for closing the door by radially pushing a cam following member engagingsaid spring away from the center of rota-. tion of said cam, and wherein closing return movement of said spring is retarded by a hydraulic checking device,,said cam being characterized by a gradually expanding radius to tension the spring as the door is opened, the cam having a recessed portion into which the cam following member falls to hold the door open, and a sharp rise on the cam immediately before the hold-open position, so that a definite major effort is required to push thedoor-into thehold-ropen position. e

15. In a door check of the character described, a spindle on which the door is adaptedto be mounted for swinging in either direction, an actuating cam integral with the .spindle,,a spring assembly including at least, one spring under compression and av roller engaging against the said actuating cam, a cylinder body mounted be low the said spring assembly..a piston within the cylinder, a spring within the cylinder urging the piston out of the cylinder, a pivoted is the piston, an arm pivoted to the said link, a lost motion driving connection between the said arm and spindlle so arranged that when the spindle is fully restored to normal position the piston spring is less than fully compressed, and hydraulic means associated with the piston and cylinder for limiting the speed of return movement of the spindle and actuating cam.

16. In a door check mechanism, a hydraulic check system of the character described, comprising a hydraulic cylinder and piston, a high speed hydraulic discharge passageway communicating with said cylinder, a low speed hydraulic discharge passageway communicating with said cylinder, means for controlling rate of flow through each such passageway, and separate means controlled by the piston for closing the high speed passageway before the piston reaches the end of its return stroke so that the final movement of the piston discharges fluid only through the low speed passageway.

17. The combination defined in claim 16 wherein said last mentioned means includes a tapered valve stem carried by the piston and movable with it into a restricted portion of the high speed discharge passageway which is thereby gradually closed as the piston enters the cylinder.

18. In a door check of the character described, a spindle on which a door is adapted to be mounted, a actuating cam carried by said spindle, spring means including a roller engaging said actuating cam, said cam being characterized by a gradually expanding radius to thereby tension the spring means as the door is opened and provide a spring retur therefor, the cam having a recessed portion into which the roller falls to hold the door open, and a sharp rise on the cam immediately before the hold-open position, so that a definite major efiort is required to push the door into hold-open position.

MARTIN CARLSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain July 28, 1939 

